1. Field of the Invention
The present invention relates to a fuel injection device for injecting and supplying fuel toward an internal combustion engine from a fuel injection valve mounted at a throttle body, and more particularly, a structure of a fuel supply pipe in the throttle body comprising two fuel injection valves, in which a first fuel injection valve and a second injection valve are mounted at a single throttle body.
2. Description of the Conventional Art
A conventional structure of a fuel supply pipe in a throttle body comprising two injection valves is indicated in FIG. 5.
A reference numeral 30 is a throttle body in which an intake passage 31 is provided through the inside thereof. The intake passage 31 is opened and closed by a throttle valve 33 mounted at a throttle valve shaft 32. A subthrottle valve 34 is mounted at a subthrottle valve shaft 35 on the upstream side of the throttle valve 33, and opens and closes the intake passage 31.
The throttle valve 33 controls an air content flowing toward the internal combustion engine which is not illustrated in the drawings, and the subthrottle valve 34 controls an air content flowing toward the throttle valve 33.
J1 is a first fuel injection valve for injecting and supplying the fuel into an intake passage 31a on the downstream side of the throttle valve 33, and the first fuel injection valve J1 shares a fuel supply area at the time of low opening operation and intermediate opening operation of the internal combustion engine.
Further, the first fuel injection valve J1 is held between a first inserting hole 30a of the throttle body 30 and a first fuel injection valve inserting hole 36a of a first fuel distribution pipe 36. At this time, a longitudinal axial line J1a—J1a of the first fuel injection valve J1 is arranged to have a crossing angle of A° with respect to a longitudinal axial line Z—Z of the intake passage 31.
Further, the first fuel distribution valve 36 is provided with a first fuel flow-in passage 36b, which is connected with the first fuel injection valve inserting hole 36a. 
J2 is a second fuel injection valve for injecting and supplying the fuel into an intake passage 31b on the upstream side of the throttle valve 33, and the second fuel injection valve J2 shares a fuel supply area at the time of intermediate and high opening operation of the internal combustion engine.
Further, the second fuel injection valve J2 is held between a second inserting hole 30b of the throttle body 30 and a second fuel injection valve inserting hole 37a of a second fuel distribution pipe 37. At this time, a longitudinal axial line J2a—J2a of the second fuel injection valve J2 is arranged to have a crossing angle of B° with respect to the longitudinal axial line Z—Z of the intake passage 31.
Further, the second fuel distribution valve 37 is provided with a second fuel flow-in passage 37b, which is connected with the second fuel injection valve inserting hole 37a. 
In this case, the crossing angle of A° between the first fuel injection valve J1 and the intake passage 31 is acuter than the crossing angle of B° between the second fuel injection valve J2 and the intake passage 31.
That is, the crossing angle of B° is larger than the crossing angle of A°.
The reason why the crossing angle of A° of the first fuel injection valve J1 is more acute than the crossing angle of B° of the second fuel injection valve J2 as described above, is as follows. In the low and intermediate opening operations of the engine, the fuel injected from the first fuel injection valve J1 is supplied in as parallel state as possible along with the air flow flowing in the intake passage 31.
On the other hand, the reason why the crossing angle of B° of the second fuel injection valve J2 is more obtuse than the crossing angle of A° of the first fuel injection valve J1 is to prevent projecting of the second fuel injection valve J2 in the left direction in the drawings and reduce a whole size of the throttle body. Even when the crossing angle of B° of the second fuel injection valve J2 is an obtuse angle, the air flow flowing in the intake passage 31 is fast especially in the high opening operation of the throttle valve, so that the injected fuel can flow sufficiently along with the air flow.